What would cause a module's admin menu item not to show? How to debug?

Question

I'm having an issue getting a custom module's menu item to show. Normally it is set to appear to the right of the System menu item in the dashboard however it is acting abnormally.

Scenario A:

I do a clean install of CE 1.9.0.1, then install the custom module and it works perfectly. Shows as intended.

Scenario B:

I attempt to install this custom module onto the client's production 1.9.0.1 website and it refuses to show. I've verified that it is registered and enabled under System > Configuration > Advanced > Advanced. I've tried clearing every type of cache both manually and through the admin panel, I've reindexed, logged out and back in dozens of times, checked error and system logs along the way and still nothing.

My assumption is that something else on the client's site has a duplicate naming convention or similar that is overwriting my custom's modules menu item presence as it works perfectly on other sites of same version.

How would I proceed with debugging? Should I be putting logging commands somewhere in my modules controllers? Is there a better way?

Thanks in advance.

Answer 1

As my experience with admin menu, they are mentioned wether in etc/adminhtml.xml or in etc/config.xml file.

The menu can be set in these file to be available only if module is enabled like this:

     <menu>
        <mycustom_menu translate="title" module="[module_name]">
            <title>My Custom Menu Item</title>
            <sort_order>300</sort_order>
            <children>
                <!-- child items go here -->
                <subitem translate="title" module="[module_name]">
                    <title>Subitem</title>
                    <sort_order>10</sort_order>
                    <action>adminhtml/mycustom_controller/</action>
                </subitem>
                <depends>
                     <module>payment/checkmo/active</module>
                </depends>
            </children>
        </mycustom_menu>
    </menu>

So in this case, if payment > checkmo is active then this menu will be displayed.

Check if that's the case.

Answer 2

Check your system.xml file specifically the section and group nodes, try renaming them for debugging purposes, check that the xml validates, turn on logging and check for xml parsing errors